Clinical significance of intraoperative amylase levels on intra-abdominal exudates in the prediction of postoperative drain amylase levels after gastric cancer surgery

Abstract Purpose: Postoperative pancreatic fistula (POPF) is a severe complication of radical gastrectomy. Postoperative drain amylase levels (D-AMY) are correlated with POPF, but it’s not for prevention. The aim of this study is to investigate whether intraoperative amylase levels (I-AMY) of intra-abdominal exudates is associated with increased D-AMY. Methods: From April 2021 to September 2023, 112 consecutive GC patients underwent radical gastrectomy with lymphadenectomy were enrolled. We measured the I-AMY of fluid from the left upper abdominal cavity (Area A), caudate fossa at the right upper abdominal cavity (Area B), and Area B after lavage with 20 mL of saline (Lavage Area B). We analyzed the correlation of I-AMY and D-AMY on POD1 and POD3. In the mostrecent 39 patients, we tested the effectiveness of polyglycolic acid (PGA) sheets around the pancreas after lymphadenectomy to prevent POPF. Results: In 73 patients without PGA sheets, I-AMY in Area B and Lavage Area B were significantly correlated with D-AMY on POD1 and POD3 (Area B: POD1, Pearson’s r=0.737, p<0.001; POD3, r=0.457, p<0.001; Lavage Area B: POD1, r=0.652, p<0.001; POD3, r=0.353, p=0.0022). Based on a receiver operating characteristic curve analysis, the cutoff value of I-AMY for predicting BL or POPF was 1197 U/L in Area B (sensitivity: 50%, specificity: 88%) and 32 U/L in Lavage Area B (sensitivity: 81%, specificity: 52%). Unexpectedly, PGA sheets did not reduce D-AMY levels. Conclusion: Intraoperative I-AMY measurement of exudates or lavage fluids in the caudate fossa may be useful for predicting BL or POPF after radical gastrectomy.